Android通过编译源代码提供系统服务-android学习之旅（85）

通过编译android4.1.2的源代码，添加一个FregServer的系统服务，以及一个服务代理FregClient

具体分为三部分，client，common，server，common中规定了client和common的接口，和一些公共方法

client部分代码

#define LOG_TAG "FregTest"#include <utils/Log.h>#include <binder/IServiceManager.h>#include "../common/IFregService.h"int main(){ IServiceManager = defaultServiceManager(); sp<IBinder> binder = defaultServiceManager()->getService(String16(FREG_SERVICE)); //通过servicemanager获取名为xxx的Service的BpBinder代理对象 if(binder == NULL) { ALOGE("[C] Failed to get freg service: %s.\n", FREG_SERVICE); return -1; } ALOGE("[C] Got BpBinder"); sp<IFregService> service = IFregService::asInterface(binder); //将bpbinder代理对象封装为bpfregservice对象 if(service == NULL) { ALOGE("[C] Failed to get freg service interface.\n"); return -2; } ALOGE("[C] Got BpFregService"); ALOGE("[C] Reading original value from FregService.\n"); int32_t val = service->getVal(); ALOGE("[C] Result: %d.\n", val); sleep(15); ALOGE("[C] Add value 1 to FregService.\n"); val += 1; service->setVal(val); ALOGE("[C] Reading the value from FregService again:\n"); val = service->getVal(); ALOGE("[C] Result: %d.\n", val); return 0;}

mk文件

LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE_TAGS := optionalLOCAL_SRC_FILES := ../common/IFregService.cpp \ FregClient.cppLOCAL_SHARED_LIBRARIES:= libcutils libutils libbinderLOCAL_MODULE := FregClientinclude $(BUILD_EXECUTABLE)

Server部分

#define LOG_TAG "FregTest"#include <stdlib.h>#include <fcntl.h>#include <utils/Log.h>#include <binder/IServiceManager.h>#include <binder/IPCThreadState.h>#include "../common/IFregService.h"#define FREG_DEVICE_NAME "/dev/freg"class FregService : public BnFregService{public: FregService() { val = 0; ALOGE("[S] Tread: %d. In FregService().", gettid()); } virtual ~FregService() { ALOGE("[S] Tread: %d. In ~FregService().", gettid()); }public: static void instantiate() { defaultServiceManager()->addService(String16(FREG_SERVICE), new FregService()); //获取servicemanager并调用addService函数实现服务注册 ALOGE("[S] Tread: %d. instantiate(), addService-%s", gettid(), FREG_SERVICE); } int32_t getVal() { ALOGE("[S] Tread: %d. In getVal(), val-%d returned.", gettid(), val); return val; } void setVal(int32_t v) { val = v; ALOGE("[S] Tread: %d. In setVal(), val-%d set.", gettid(), val); }private: int val;};int main(int argc, char** argv){ FregService::instantiate(); ProcessState::self()->startThreadPool(); //启动线程池ALOGE("[S] Tread: %d. ProcessState::self()->startThreadPool() finished.", gettid()); IPCThreadState::self()->joinThreadPool(); //将主线程加入线程池ALOGE("[S] Tread: %d. IPCThreadState::self()->joinThreadPool(); finished.", gettid()); return 0;}

LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE_TAGS := optionalLOCAL_SRC_FILES := ../common/IFregService.cpp \ FregServer.cppLOCAL_SHARED_LIBRARIES:= libcutils libutils libbinderLOCAL_MODULE := FregServerinclude $(BUILD_EXECUTABLE)

common部分

#define LOG_TAG "IFregService"#include <utils/Log.h>#include "IFregService.h"using namespace android;enum{ GET_VAL = IBinder::FIRST_CALL_TRANSACTION, SET_VAL};class BpFregService: public BpInterface<IFregService> //通信请求的发送{public: BpFregService(const sp<IBinder>& impl) : BpInterface<IFregService>(impl) { }public: int32_t getVal() { Parcel data; data.writeInterfaceToken(IFregService::getInterfaceDescriptor()); //获取了Ifregservice的接口名，并调用了parcel.writeInterfaceToken函数写入了data中 Parcel reply; remote()->transact(GET_VAL, data, &reply); //remote获取bpbinder代理对象，通过transact函数来发送请求 int32_t val = reply.readInt32(); return val; } void setVal(int32_t val) { Parcel data; data.writeInterfaceToken(IFregService::getInterfaceDescriptor()); data.writeInt32(val); Parcel reply; remote()->transact(SET_VAL, data, &reply); }};IMPLEMENT_META_INTERFACE(FregService, "hikame.IFregService");//见最下status_t BnFregService::onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) //通信数据的接收与处理{ switch(code) { case GET_VAL: { CHECK_INTERFACE(IFregService, data, reply); int32_t val = getVal(); reply->writeInt32(val); return NO_ERROR; } case SET_VAL: { CHECK_INTERFACE(IFregService, data, reply); int32_t val = data.readInt32(); setVal(val); return NO_ERROR; } default: { return BBinder::onTransact(code, data, reply, flags); } }}/*IFregService的具体实现#define IMPLEMENT_META_INTERFACE(INTERFACE, NAME) \ const android::String16 I##INTERFACE::descriptor(NAME); \ const android::String16& \ I##INTERFACE::getInterfaceDescriptor() const { \ return I##INTERFACE::descriptor; \ } \ android::sp<I##INTERFACE> I##INTERFACE::asInterface( \ const android::sp<android::IBinder>& obj) \{ \ android::sp<I##INTERFACE> intr; \if (obj != NULL) { \ intr = static_cast<I##INTERFACE*>( \ obj->queryLocalInterface( \ I##INTERFACE::descriptor).get()); \if (intr == NULL) { \ intr = new Bp##INTERFACE(obj); \} \} \ return intr; \} \ I##INTERFACE::I##INTERFACE() { } \ I##INTERFACE::~I##INTERFACE() { } \*/

#ifndef IFREGSERVICE_H_#define IFREGSERVICE_H_#include <utils/RefBase.h>#include <binder/IInterface.h>#include <binder/Parcel.h>#define FREG_SERVICE "hikame.FregService" //Service名称using namespace android; //在各个头文件中namespace为android的代码部分都被使用了class IFregService: public IInterface{public: /*#define DECLARE_META_INTERFACE(INTERFACE) \ static const android::String16 descriptor; \ static android::sp<I##INTERFACE> asInterface( \ const android::sp<android::IBinder>& obj); \ virtual const android::String16& getInterfaceDescriptor() const; \ I##INTERFACE(); \ virtual ~I##INTERFACE(); \ 定义了构造函数和析构函数，descriptor是接口名，getInterfaceDescriptor是获取该接口名的函数 ？？这个android::sp是什么？A：/include/utils/StrongPointer.h */ DECLARE_META_INTERFACE(FregService); virtual int32_t getVal() = 0; virtual void setVal(int32_t val) = 0;};class BnFregService: public BnInterface<IFregService>{public: virtual status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags = 0);};#endif

好了放他们放到android-4.1.2_r1-JZO54K\external\binder目录下， external目录下可以放这些外来的服务

执行编译命令

1.通过xShell连接到远程的ubuntu服务器，里面下载了Android源代码

2.cd 到相应版本源代码的根目录

3.执行source build/envsetup.sh初始化环境

4.执行mmm ./external/binder/server/

5.执行mmm ./external/binder/client/ ,分别编译两个模块

6然后在out/target/product/gerneric/system/bin目录底下，查看相应的生成文件

下一步是把相应的服务文件拷贝到手机的/data/local/tmp目录下

1.代开adb shell，执行su，进入root模式

2.在服务文件的目录，按住shift右键，打开命令窗口

3.输入adb push FregServer /data/local/tmp，adb push FregClient /data/local/tmp，拷贝到相应的目录

4.su进入root模式，进入 /data/local/tmp目录，执行./FregClient

5.查看日志adb logcat FregTest：i *：s

部分截图